International Space Station Mobile Dosimetry Unit: A Comparison of Flight Measurements With Model Calculations

Abstract

Space radiation measurements were made on the International Space Station (ISS) with the Bulgarian Liulin-E094 Mobile Dosimetry Units (MDU) during 2001. The Liulin-E094 was part of the Dosimetric Mapping experiment lead by Dr. G. Reitz, DLR. Four MDUs were placed at fixed locations: one unit in the ISS Unity Node-1 and three units were located in the US Laboratory module. Space radiation flight measurements were obtained during the time period May 11 - July 26, 2001. In this paper we discuss the development of an MDU shielding model using combinatorial geometry and 3-D visualization and the orientation and placement at the four locations within the ISS. Four shielding distributions were generated for the combined ISS and MDU shielding models. The AP8MAX trapped proton model was used to compute the daily absorbed dose for the four MDUs and are compared with the flight measurements. In addition, the trapped proton anisotropy (East-West effect) was measured for several passes through the South Atlantic Anomaly. Future plans are to compare these measured anisotropic results with computational methods using the Badhwar-Konradi anisotropic model /1/.